#include <bits/stdc++.h>
using namespace std;

int main ()
{
    std::set<int> myset;
    std::set<int>::iterator it;
    std::pair<std::set<int>::iterator,bool> ret;

    // set some initial values:
    for (int i=1; i<=5; ++i) myset.insert(i*10);    // set: 10 20 30 40 50

    ret = myset.insert(20);               // no new element inserted
            cout<<"ret"<<ret.second<<end;
    if (ret.second==false) it=ret.first;  // "it" now points to element 20

    myset.insert (it,25);                 // max efficiency inserting
    myset.insert (it,24);                 // max efficiency inserting
    myset.insert (it,26);                 // no max efficiency inserting

    int myints[]= {5,10,15};              // 10 already in set, not inserted
    myset.insert (myints,myints+3);

    std::cout << "myset contains:";
    for (it=myset.begin(); it!=myset.end(); ++it)
        std::cout << ' ' << *it;
    std::cout << '\n';

    return 0;
}